/**
 * Created by Administrator on 2017/11/27.
 */
public class Test2 {
        public static void main (String [] args) {
            StringBuffer s1= new StringBuffer ("AB"); StringBuffer s2 = new StringBuffer ("CD"); operate (s1,s2);
            System.out.println("s1="+s1+" s2="+s2); }
        static void operate(StringBuffer x, StringBuffer y){ x.append(y);
            x= y;
        }
    }
